如何自定义拼接设置UserAgent参数

import { webview } from '@kit.ArkWeb' 
 
@Entry 
@Component 
struct Index { 
  private controller: webview.WebviewController = new webview.WebviewController() 
  @State userAgentPa: string = '' 
  build() { 
    Row() { 
      Column() { 
        Web({ src: 'http://www.example.com', controller: this.controller }) //需要手动替换为真实网站 
          .width('100%') 
          .userAgent(this.userAgentPa) 
          .onUrlLoadIntercept((event) => { 
            let userAgent = this.controller.getUserAgent(); 
            this.userAgentPa = userAgent + ' 111111111' 
            return false; 
          }) 
      } 
      .width('100%') 
    } 
    .height('100%') 
  } 
}